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Related papers: Scattering analysis of LOFAR pulsar observations

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Pulsars have been primarily detected by their narrow pulses or periodicity in time domain data. Interferometric surveys for pulsars are challenging due to the trade-off between beam sensitivity and beam size and the corresponding tradeoff…

High Energy Astrophysical Phenomena · Physics 2024-07-26 Jitendra Salal , Shriharsh P. Tendulkar , Visweshwar Ram Marthi

In this work we study the wave scattering by small dispersionless particles with pulsating refractive index. The scattered fields and their resonance frequencies are calculated by using scalar approximation and exponentially time-dependent…

Optics · Physics 2023-10-12 V. V. Prosentsov

We study the energy-dependent pulse profile of 4U 1538-52 and its phase-dependent spectral variability, with emphasis on the behavior around the cyclotron resonant scattering feature at around 21 keV. We analyze all available NuSTAR…

We compare signal and noise for observations of the scintillating pulsar B0834+06, using very-long baseline interferometry and a single-dish spectrometer. Comparisons between instruments and with models suggest that amplitude variations of…

Astrophysics of Galaxies · Physics 2015-05-27 C. R. Gwinn , M. D. Johnson , T. V. Smirnova , D. R. Stinebring

Context. High-precision pulsar-timing experiments are affected by temporal variations of the Dispersion Measure (DM), which are related to spatial variations in the interstellar electron content. Correcting for DM variations relies on the…

The frequency dependence of pulse width is studied for 150 normal pulsars, mostly selected from the European Pulsar Network, for which the 10\% multifrequency pulse widths can be well fit with the Thorsett relationship…

High Energy Astrophysical Phenomena · Physics 2015-06-22 J. L. Chen , H. G. Wang

A subset of magnetic stars exhibit periodic radio pulses produced by the coherent electron cyclotron maser mechanism. These pulses are known to exhibit both temporal and spectral variations, which have been attributed to phenomena intrinsic…

Solar and Stellar Astrophysics · Physics 2026-04-21 J. S. Morgan , B. Das , H. E. Bignall

We have used sensitive LOw Frequency ARray (LOFAR) observations of PSR B0809+74 at 15--62 MHz to study the anomalously intensive pulses, first reported by Ulyanov et al. (2006) at 18--30MHz. Similarly to Ulyanov et al., we found that the…

High Energy Astrophysical Phenomena · Physics 2018-08-22 X. Song , V. I. Kondratiev , A. V. Bilous

Solar radio bursts are strongly affected by radio-wave scattering on density inhomogeneities, changing their observed time characteristics, sizes, and positions. The same turbulence causes angular broadening and scintillation of galactic…

We present here the results from an extensive scintillation study of twenty pulsars in the dispersion measure (DM) range 3 - 35 pc cm^-3 carried out using the Ooty Radio Telescope, to investigate the distribution of ionized material in the…

Astrophysics · Physics 2009-10-30 N. D. Ramesh Bhat , Yashwant Gupta , A. Pramesh Rao

We present the astrometric identification of 80 known radio pulsars as unresolved continuum sources detected at 144 MHz in the second data release of the LOFAR Two-metre Sky Survey (LoTSS DR2), which covers 27% of the Northern hemisphere.…

High Energy Astrophysical Phenomena · Physics 2026-02-18 G. A. C. Rijkers , C. G. Bassa , J. R. Callingham , T. Shimwell

Context: Accretion-powered X-ray pulsars show highly energy-dependent and complex pulse-profile morphologies. Significant deviations from the average pulse profile can appear, in particular close to the cyclotron line energies. These…

Recent pulsar scintillation measurements from Ooty, in conjunction with those from Parkes and other large radio telescopes, are used for a systematic investigation of the Local Interstellar Medium (LISM) towards the general direction of the…

Astrophysics · Physics 2009-11-07 N. D. Ramesh Bhat , Yashwant Gupta

Radio pulsars, as highly coherent point sources, serve as powerful probes of the ionized interstellar medium (IISM). Pulsar scintillation observations have revealed inverted arclets on the secondary spectrum, indicating quasilinearly…

Astrophysics of Galaxies · Physics 2026-04-14 Zhu Xu , Xun Shi

The results of simultaneous multifrequency observations of giant radio pulses from the Crab pulsar, PSR B0531+21, at 23, 111, and 600 MHz are presented and analyzed. Giant pulses were detected at a frequency as low as 23 MHz for the first…

The Indian Pulsar Timing Array (InPTA) collaboration has recently made its first official data release (DR1) for a sample of 14 pulsars using 3.5 years of uGMRT observations. We present the results of single-pulsar noise analysis for each…

The interstellar medium hosts a population of scattering screens, most of unknown origin. Scintillation studies of pulsars provides a sensitive tool for resolving these scattering screens and a means of measuring their properties. In this…

High Energy Astrophysical Phenomena · Physics 2022-03-14 James W. McKee , Hengrui Zhu , Daniel R. Stinebring , James M. Cordes

Refractive interstellar scintillation (RISS) is thought to be the cause behind a variety of phenomena seen at radio wavelengths in pulsars and compact radio sources. Though there is substantial observational data to support several…

Astrophysics · Physics 2009-10-31 N. D. Ramesh Bhat , A. Pramesh Rao , Yashwant Gupta

We analytically treat the scattering of two counter-propagating photons on a two-level emitter embedded in an optical waveguide. We find that the non-linearity of the emitter can give rise to significant pulse-dependent directional…

Quantum Physics · Physics 2015-06-24 Anders Nysteen , Dara P. S. McCutcheon , Jesper Mørk

We have detected significant Rotation Measure variations for 9 bright pulsars, as a function of pulse longitude. An additional sample of 10 pulsars showed a rather constant RM with phase, yet a small degree of RM fluctuation is visible in…

Astrophysics of Galaxies · Physics 2015-05-13 A. Noutsos , A. Karastergiou , M. Kramer , S. Johnston , B. W. Stappers